Import DAE (collada) does nothing
This is more for reference for other users having issues with the DAE Format.
It could be that the Collada DAE version being used for your assets is 1.4.0, where as Blender only seems to read 1.4.1
Try using Autodesk's FBX Converter tool on the DAE files and you will be able to use your files in Blender.